Sifters and classifiers for materials



June 8, 1965 F. s. GARCES 3,187,394

SIFTERS AND CLASSIFIERS FOR MATERIALS Filed May 19, 1961 2 Sheets-Sheet l TIL/P5 5 0x p/Ms WiLIQZ ATTORNEY:

June 8, 1965 F. s. GARCES 3,137,394

SIFTERS AND CLASSIFIERS FOR MATERIALS Filed May 19, 1961 2 Sheets-Sheet 2 1-5. 'z if [:1 37

2f 29 la! if 47 g A; if 3 5 Ell INV EN TOR Fae/P4: 5'44 2; 644 6615 ATTORNEY5 United States Patent SIFTERS AND CLASSIFIERS FOR MATERIALS Felipe Salete Garces, MexicoCity, Mexico, assignor to Refaccionaria de Molinos, S.A., Mexico City, Mexico Filed May 19, 1961, Ser. No. 111,297 2 Claims. (Cl. 209-819) This invention relates to the sitting and classifying of materials, specifically related to a sitter or classifier for ground products.

The sitters already known have several drawbacks that could not have been solved until now, and some of these machines have the sieves placed one on the other pressed altogether by means of vertical tighening rods with fixing nuts. This system has the serious drawback that for taking out or separating the lower or intermediate sieves it is necessary, first, to loosen the fixing nuts of the tightening rods, separating all the upper sieves until the sieve is reached that it is desired to remove, with time and corresponding money losses.

There is another system of sitters in which the sieves are located as drawers on suitable fixed guides in casings, and while this does not have the disadvantages mentioned, it has the drawback that the sieves can never be hermetically secured for the reason that it cannot be pressed. The latter is due to the fact that as the fixed guides will not permit a pressing action consequently spaces remain and thus the materials escape mixing up with others. If it is desired to prevent the escape of material, rubber, felt or other seals may be used, but the sieves will remain so tightly fixed that the operation of taking them out or in will become very difiicult. 1

It is one of the objects of this invention to present a sitter having a special device that eliminates the various drawbacks referred to. Another object of this invention resides in a sitter which besides securing a perfect fit between the sieves will easily permit the removal or insertion of the sieves.

A further object of this invention resides in a sitter apparatus having sets of articulated arms in which the sieves are hung or suspended, and these articulated arms permit the vertical displacement of the sieves which are lifted or pressed by the action of a pressing elevating mechanism located underneath all the sieves of each section.

Further objects will be apparent from the following description when considered in connection with the accompanying drawings in which;

FIGURE 1 is a side elevation partly in section of the sitter apparatus of this invention,

FIG. 2 is an end elevation of the apparatus of FIG. 1,

FIG. 3 is a partial top plan view of the apparatus of FIGS. 1 and 2,

FIG. 4 is a side view of a detail of the articulated arms,

FIG. 5 is an end view between two sections illustrated in FIG. 1,

FIG. 6 is a transverse section showing the lower part of the sitter illustrating the elevating-pressing mechanism,

FIG. 7 is a sectional view transverse to that of FIG. 6,

FIG. 8 shows a top plan view of the mechanism of FIGS. 6 and 7,

FIG. 9 shows a sectional plan view of a closed door to cover the sieves of the present invention,

FIG. 10 is a plan view partly in section of FIG. 9 but with the door open,

' FIG. 11 is a sectional view showing the details of the locking device of the door, and

FIG. 12 is a sectional plan view showing the door in a position parallel to the sieves and just prior to the closing thereof.

Specifically referring to the drawings and precisely to FIGS; 1, 2, and 3, there is shown a sitter according to the 3,187,894 Patented June 8, 1965 ice present invention with three sieve sections, the left section indicated as sieves 1, separated from the other two sections 32 and 33 with sieves tightly held together.

The sieves 1 are located one over another, forming sieve sections where the sieves are piled in a column. The sieves are suspended from the hanging arms 2 which are articulated by means of bolts 3 from the vertical support or frame 4. The articulated arms or links 2 have in their center a bolt 5 which acts as a stop on the frame 4 when the sieves 1 are lowered down. The sieves are supported by a'third bolt 6 which is placed at the free end of the articulated arms 2 and this bolt 6 is slightly introduced into the groove 22 at the side part of each sieve as clearly indicated in FIG. 5. r

The bolts 3, which articulate the arms 2 relative to the frame 4, have at the external part a helical spring 7, supported by one of its ends on the external face of the frame 4, and the other end on a lockwasher 23, fixed in its proper position on bolt 3 by means of a cotter pin 24, as clearly indicated in FIGS. 4 and 5.

Since the grooves 22 at the side part of sieve 1 extend along the length of the sieves, they can be pulled out easily when they are loosened as shown in FIGS. 4 and 5 by just pulling the sieve out and consequently sliding the groove over the bolt 6, until the sieve is completely taken out.

It is obvious that each sieve must have at least two articulated arms, but it may have more than two arms, depending on the dimensions of the sieves.

The sieves alreadyplaced in position on the bolts 6 of the articulated arms 2, as shown in FIG. 4, are pressed together as a unit by means of the elevating mechanism located at the bottom of each sieve section as indicated in FIGS. 1 and 2. r

The elevating mechanism for the sieves consists of means at the bottom of the pile on which the first lower sieve is supported on 13, as clearly indicated in FIG. 6. The piece 13 is adjusted to a plate 25 which has in its lower surface a plurality of hangers 26, forming square sets supported by crossed angle steel bars 27.

On these hangers 26 and integrally attached to plate 25 is a lever or arm 12, articulated to the same by means of a bolt 28, and the other end is articulated to a nut 9, supported by ball bearings 10 which slide on angular rails 11.-

There is a nut for each of the two levers 12 ot the elevating mechanism and each one is screwed onto a screw spindle which is threaded halt right and half left as indicated in FIG. 6 at 8.

The screw 8 is supported by both ends on suitable bearings and its front end overpasses the elevating mechanism housing and provided with a crank 29 by means of which the screw is turned to actuate both articulated levers 12 by changing its inclination as shown in FIG. 6. The levers 12 gradually move to a more vertical position and consequently lifting plate 25 with the sieve pile bottom 13 consequently pressing the sieves to each other to thereby obtain a hermetic seal between the sieves.

From the above explanation, it may be understood that when actuating the elevating mechanism, first the lower sieve is elevated from the bottom of the sieve pile and pressed to the next one up above until the last one is on top, and thereby the required eitort to press the sieves is reduced to a minimum.

The sieves being thus freely suspended from articulated levers 2 by its grooves 22, there is a looseness in the joints which when the sieves are pressed by the elevating mechanism are perfectly aligned in vertical direction. In other words, it may be unaligned in said vertical direction. To avoid this difficulty which may cause leakage when operators are careless, there is placed at each side of the vertical sieve pile a cover or special door 14 hinged at 15 and which has a pair of angular guides 16 having ribs 30 located, at the. front and rear sides of each sieve to thus secure, when closing the doors 14, one at the front and other at the rear of the vertical sieve piles, all the sieves becoming perfectly aligned in the vertical direction for its elevation, thus'closing hermetically the device for'proper points relative, to the sieves a certain distance and then,

will swing on its hinged arm.

Thus, the covervor door,.FIG. 10,; from the open to the closed position rotates n pivot 14' as to the arm 15 and the cover 14 counter, clockwise and atrthe same time the cover l4rpivotsraround the pivot 15 in a clockwise rota! tion.

The angular guides 16. on the doors. may be adjusted to its. right position, whichmay be changed according to requirements by means of. slides inthe supports 31, inside. of which there are. placed bolt and nut units. for fixing them to any position. The. door 14locks by means of a latch 20, FIG. 11, whichlatches to the internal face of the frame as clearly indicated inFIG. 9.

The latch 20, is. jointed at one of its ends with a spinning rod end 19, the opposite end being jointed to a key 18 forv opening; and. closing. the. latch. with the key 18 being located inside of 'arfixed knob, which is also. used as a pull for the door. 7 V i To avoid the hinge'arms from'presenting an insuificient lock action, the lock remains hidden when the door is closed since the end: door passes the hinge arm which is completely covered when the door is closed, as indicated in the closed door position illustrated in FIG. 9.

I claim:

1. Asifter orclassifierof ground material comprising a.

hinged to the frame and the other end provided with a bolt thatprojects into a continuous groove at the side face of the sieve, an elevating mechanism mounted on the bottom ofthe pile of sieves including a screw spindle and levers with the spindleconnected to one end of each lever and having the other end of each lever bearing against the bottom of the sieve pile by a pivotal connection, each sieve, pile being supported on a plate adjacent and above the elevating mechanism, means to rotate said spindle so that said elevating mechanism will press the sieves firmly in place by the screw spindle operating its levers, and each of said articulated arms having one intermediate bolt that acts as a. stop to fixthe position of the sieves.

2; A sifter or classifier of ground material comprising a frame, a plurality of sifting sections in the frame with each section having a plurality of individual sieves provided ina verticalpile, at least two articulated arms for each sieve, each articulated arm having one of its endshinged to the frame and the other end provided with a bolt that projects into acontinuous groove at the side face of the sieve, an elevating mechanism. at the. bottom of each sieve pile, each sieve pile being supportedon a plate ad- .jacent and above the. elevating mechanism, said elevating mechanism having a screw spindle and levers for pressing said plurality of, sieves firmly together on rotation of said spindle, front and rear doors provided to-cover the sieve sections, and the front and rear doors having adjustable angular guides. which align the sieves to the correct posi-' tion fixed to the front door by meansof. a complementary rib at front and rear sides ofthe sieves whereby both ribs will contact their angular guides, and. each door has in-.

ternal hinged arms. rota-ting onv pivots. on the frame and rotating on pivots on the door intermediate its sides. so thatthe door will separate parallel to andsimultaneously at all points relative. to the sieves to. a certain distance and thereafter will swing on. its. pivots.

References. Cited by the Examiner UNITED 9 STATES PATENTS 788,616 5/05' Werts 209 404 1,566,036 12/25 Nachtsheim '209 34s 1,891,496 12/32 Bedford 76-22 2,957,578 10/60 Ball 209-319 3,022,893 2/62 Hasley 209-404 FOREIGN. PATENTS.

695,951 8/53 Great Britain. 712,666, 7/54. G'reatBritainj OTHER REFERENCES; American Millerand Processor, page 64, April 4, 1949. HARRY B; THORNTON, Primary Examiner;

HERBERT L. MARTIN, JAMES MICHAEL,

- 6 Examiners. 

1. A SIFTER OR CLASSIFIER OF GROUND MATERIAL COMPRISING A FRAME, A PLURALITY OF SIFTING SECTIONS IN THE FRAME WITH EACH SECTION HAVING A PLURALITY OF INDIVIDUAL SIEVES PROVIDED IN A VERTICAL PILE, AT LEAST TWO ARTICULATED ARMS FOR EACH SIEVE, EACH ARTICULATED ARM HAVING ONE OF ITS END HINGED TO THE FRAME AND THE OTHER END PROVIDE WITH A BOLT THAT PROJECTS INTO A CONTINUOUS GROOVE AT THE SIDE FACE OF THE SIEVE, AN ELEVATING MECHANISM MOUNTED ON THE BOTTOM OF THE PILE OF SIEVES INCLUDING A SCREW SPINDLE AND LEVERS WITH THE SPINDLE CONNECTED TO ONE END OF EACH LEVER AND HAVING THE OTHER END OF EACH LEVER BEARING AGAINST THE BOTTOM OF THE SIEVE PILE BY A PIVOTAL CONNECTION, EACH SIEVE PILE BEING SUPPORTED ON A PLATE ADJACENT AND ABOVE THE ELEVATING MECHANISM, MEANS TO ROTATE SAID SPINDLE SO THAT SID ELEVATING MECHANISM WILL PRESS THE SIEVES FIRMLY IN PLACE BY THE SCREW SPINDLE OPERATING ITS LEVERS, AND EACH OF SAID ARTICULATED ARMS HAVING ONE INTERMEDIATE BOLT THAT ACTS AS A STOP TO FIX THE POSITION OF THE SIEVES. 